﻿using System;
using System.Security.Cryptography;
using System.Text;
using log4net;

namespace Koonsoft.HYCRM.BLL
{
    /// <summary>
    /// 加解密助手
    /// </summary>
    public class EncryptHelper
    {
        private static ILog logger = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// 进行DES加密。
        /// </summary>
        /// <param name="pToEncrypt">要加密的字符串。</param>
        /// <param name="sKey">密钥，且必须为8位。</param>
        /// <returns>以Base64格式返回的加密字符串。</returns>
        public static string Encrypt(string pToEncrypt, string sKey)
        {
            using (var des = new DESCryptoServiceProvider())
            {
                try
                {
                    byte[] inputByteArray = Encoding.UTF8.GetBytes(pToEncrypt);
                    des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
                    des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
                    var ms = new System.IO.MemoryStream();
                    using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write))
                    {
                        cs.Write(inputByteArray, 0, inputByteArray.Length);
                        cs.FlushFinalBlock();
                        cs.Close();
                    }
                    string str = Convert.ToBase64String(ms.ToArray());
                    ms.Close();
                    return str;
                }
                catch (Exception ex)
                {
                    logger.Error("DES加密失败", ex);
                    return string.Empty;
                }
            }
        }

        /// <summary>
        /// 进行DES解密。
        /// </summary>
        /// <param name="pToDecrypt">要解密的以Base64</param>
        /// <param name="sKey">密钥，且必须为8位。</param>
        /// <returns>已解密的字符串。</returns>
        public static string Decrypt(string pToDecrypt, string sKey)
        {
            byte[] inputByteArray = Convert.FromBase64String(pToDecrypt);
            using (var des = new DESCryptoServiceProvider())
            {
                try
                {

                    des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
                    des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
                    System.IO.MemoryStream ms = new System.IO.MemoryStream();
                    using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write))
                    {
                        cs.Write(inputByteArray, 0, inputByteArray.Length);
                        cs.FlushFinalBlock();
                        cs.Close();
                    }
                    string str = Encoding.UTF8.GetString(ms.ToArray());
                    ms.Close();
                    return str;
                }
                catch (Exception ex)
                {
                    logger.Error("DES解密失败", ex);
                    return string.Empty;
                }
            }
        }
    }
}
